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Fysikere opdager 'negativ masse'

Foto: Jørgen True/SBi

Fysikere har haft succes med at lave en væske med negativ masse, der kommer mod dig, når du skubber den væk fra dig. Dermed bryder væsken Newtons love. Opdagelsen blev gjort, da forskere fra Washington State University kølede Rubidium-atomer ned til omkring det absolutte nulpunkt.


via New York Times 28. apr 2017 08:55

Dna fra fortidsmenneske trækkes ud af jord

Kommentarer (13)

Negativ masse blev opdaget for syv år siden:

Forschungsverbund Berlin e.V. (FVB) (2010, April 19). Negative mass and high speed: How electrons go their own ways. ScienceDaily:
Citat: "...
Physicists of the Max Born Institute in Berlin report in the latest issue of Physical Review Letters that electrons in semiconductor crystals have a negative inertial mass when strongly accelerated in an electric field.
Researchers from the Max Born Institute in Berlin have now demonstrated that crystal electrons in extremely high electric fields exhibit a completely different behavior. Their mass even becomes negative.
This means that the acceleration is in opposite direction to the force, which can only be explained by a negative inertial mass of the electron.
The new results agree with calculations of the Nobel Prize winner Felix Bloch undertook more than 80 years ago. They open up a new regime of charge transport with new possibilities for future microelectronics devices. The observed frequencies are in the terahertz range (1 THz = 1000 GHz = 10^12Hz), about 1000 times higher than the clock rate of the newest PCs.


Gud spiller med anakroniske ikke-deterministiske terninger?:

Washington University in St. Louis. (2015, February 9). In the quantum world, the future affects the past: Hindsight and foresight together more accurately 'predict' a quantum system’s state. ScienceDaily:
Citat: "...
The orthodox view is that this indeterminacy is not a defect of the theory, but rather a fact of nature. The particle's state is not merely unknown, but truly undefined before it is measured. The act of measurement itself that forces the particle to collapse to a definite state.
It's as if what we did today, changed what we did yesterday. And as this analogy suggests, the experimental results have spooky implications for time and causality -- at least in microscopic world to which quantum mechanics applies.
The shattering thing about the retrodiction is that it is 90 percent accurate. When the physicists check it against the stored measurement of the system's earlier state it is right nine times out of 10.
For one thing, it suggests that in the quantum world time runs both backward and forward whereas in the classical world it only runs forward.
In a world where time is symmetric, however, is there such a thing as cause and effect? To find out, Murch proposes to run a qubit experiment that would set up feedback loops (which are chains of cause and effect) and try to run them both forward and backward.
"It takes 20 or 30 minutes to run one of these experiments," Murch said, "several weeks to process it, and a year to scratch our heads to see if we're crazy or not."
"At the end of the day," he said, "I take solace in the fact that we have a real experiment and real data that we plot on real curves."

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Det er næppe rigtig negativ masse. Hvis det er negativ masse, vil det kunne bruges til at lave flyvende gafler og tallerkener. Og flyvende gafler og tallerkener findes ikke. Hvis der eksisterer negativ masse, er det kun i meget kort tid, og det vil hurtigt forsvinde sammen med en positiv masse, som det eksisterer sammen med, og uden der frigives energi eller støj.

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